Barrels, drums and the like of sheetmetal with end closures of the type described have been provided heretofore by rolling, welding, soldering or brazing the sheetmetal cover or bottom to the rim of the sheetmetal generally cylindrical body.
It is known in connection with thin sheet metals and the fabrication of food preservative cans, for example, to attach the bottom or cover by a folding operation (see German Patent No. 733 200) in which a folding operation which also is supported by a resistance welding of interfitting parts is used to seal the cover or bottom to the cylindrical body. A stiffening bend is provided for the edges in this arrangement.
It is also known to weld prefolded or partly prefolded cover or bottom arrangements to a body of a container from German Open Application No. DE-OS 35 46 458, thereby eliminating the need for sealing masses to ensure an effective seal at the cover or bottom. In this case, however, three interfitting sheetmetal layers are joined together by the weld seam which is preferably made by a laser beam.
German Open Application No. DE-OS 36 00 532 describes the formation of containers in which the bottom and the container body are welded together without interfolding or with a minimum of folding and without speed sealing means other than the folding and welding.
In the past it has been a problem to provide by the techniques described, large stable containers especially barrels or drums in a simple and economical manner and in such fashion as to enable the various steps in the process of making the container to be separated or performed at different locations.